Global geoid model GGM2022

We provide an updated 5 $^\prime$ $\times$ 5 $^\prime$ global geoid model GGM2022, which is determined based on the shallow layer method (Shen method). First, we choose an inner surface $\Gamma$ below the EGM2008 global geoid by 15 m, and the layer bounded by the inner surface $\Gamma$ and the Earth's geographical surface $S$ is referred to as the shallow layer. The Earth's geographical surface $S$ is determined by the digital topographic model DTM2006.0 combining with the DNSC2008 mean sea surface. Second, we formulate the 3D shallow mass layer model using the refined 5 $^\prime$ $\times$ 5 $^\prime$ crust density model CRUST$_-$re , which { is an improved 5 $^\prime$ $\times$ 5 $^\prime$ density model of the CRUST2.0 or CRUST1.0 with taking into account the corrections of the areas covered by ice sheets and the land-ocean crossing regions. Third, based on the shallow mass layer model and the gravity field EGM2008 that is defined in the region outside the Earth's geographical surface $S$, we determine the gravity field model EGM2008s that is defined in the whole region outside the inner surface $\Gamma$, where the definition domain of the gravity field is extended from the domain outside $S$ to the domain outside $\Gamma$. Fourth, based on the gravity field EGM2008s and the geodetic equation $W(P)=W_0$ (where $W_0$ is the geopotential constant on the geoid and $P$ is the point on the geoid $G$), we determine a 5 $^\prime$ $\times$ 5 $^\prime$ global geoid, which is referred to as GGM2022. Comparisons show that the GGM2022 fits the globally available GPS/leveling data better than EGM2008 global geoid in the USA, Europe and the western part of China.Comment: 17 pages, 25 figure

Features and influencing mechanisms of gaseous elemental mercury over the equatorial Pacific and their differences with the Southern Ocean

Due to the harmful impacts on the ecosystem and even human health, mercury (Hg) compounds in the environment deserve serious concern. Atmospheric mobilization and exchange at the air-sea interface are important processes in biogeochemical cycling of Hg. Relying on the 30th (2013/2014), 31st (2014/2015), and 33rd (2016/2017) Chinese National Antarctic Research Expedition aboard R/V Xuelong, we found significant rising gaseous elemental mercury (GEM) concentrations over the equatorial Central Indo-Pacific region. Excluding the contribution of anthropogenic, volcanic and biomass burning emissions, the enhanced GEM in marine boundary layer was likely due to the combined actions of two driving factors drove by the Inter-Tropical Conversion Zone (ITCZ): (1) intense wet deposition of Hg, followed by subsequent rapid photoreduction and vast evasion from the surface sea; and (2) the regional low-level convergence of airflow that caused the mass accumulation of GEM in air. In addition, apparently higher GEM concentration level in the equatorial Central Indo-Pacific than in the Southern Ocean was observed in one cruise. Further investigation suggests that apart from the ITCZ corresponded mechanisms, the effects of spatial differences in anthropogenic emissions and more significant GEM oxidation in Antarctic sea should play roles in this phenomenon

Hyperforin Promotes Post-stroke Neuroangiogenesis via Astrocytic IL-6-Mediated Negative Immune Regulation in the Ischemic Brain

Hyperforin has been shown to be capable of promoting angiogenesis and functional recovery after ischemic stroke in our previous study. However, the exact mechanisms involved are not fully elucidated. In this study, adult male mice were subjected to 60-min transient middle cerebral artery occlusion followed by reperfusion for 28 days. Hyperforin was administrated to MCAO mice every 24 h for 2 weeks starting at 14 days post-ischemia (dpi). Then flow cytometry, quantitative Real-time PCR (RT-qPCR), western blotting, immunohistochemistry, and functional assays were performed to explore the molecular mechanisms in vivo and in vitro. Our data showed that hyperforin increased astrocytic interleukin (IL)-6 in the ischemic hemisphere via TLR4 at 28 dpi. The astrocytic IL-6 was essential to the promoting effects of hyperforin on the neural precursor cells proliferation, neuronal differentiation, angiogenesis, and functional recovery after stroke. Furthermore, hyperforin promoted the infiltration of regulatory T cells (Tregs) to the ischemic hemisphere and increased Tregs-derived cytokine IL-10 and transforming growth factor-β (TGF-β) in a manner that was dependent on astrocytic IL-6. Astrocytic IL-6 was critical to the role of hyperforin in promoting the infiltration of T-helper (Th) type 2 cells to the ischemic hemisphere and Th2-derived cytokine IL-4, relative to Th1 and Th1-derived cytokine interferon-γ (IFN-γ), which decreased during stroke recovery. After depletion of CD25+ Tregs, the promoting effects of hyperforin on post-stroke neurogenesis was attenuated. Moreover, blockade of IL-4 and TGF-β abrogated the promoting role of hyperforin in post-stroke neurogenesis, angiogenesis and functional recovery. Our results reveal a previously uncharacterized role of astrocytic IL-6-mediated negative immune regulation in the promoting effects of hyperforin on post-stroke neurovascular regeneration and functional recovery

Complete CSC Hypersurfaces Satisfying an Okumura-Type Inequality in Ricci Symmetric Manifolds

We investigate the spacelike hypersurface with constant scalar curvature (SCS) immersed in a Ricci symmetric manifold obeying standard curvature constraints. By supposing these hypersurfaces satisfy a suitable Okumura-type inequality recently introduced by Meléndez, which is a weaker hypothesis than to assume that they have two distinct principal curvatures, we obtain a series of umbilicity and pinching results. In particular, when the Ricci symmetric manifold is an Einstein manifold, then we further obtain some rigidity classifications of such hypersufaces

Wetlands conservation in Beijing of China: Present status and development strategies

The urbanization in Beijing intensified the fragmentation of ecosystems, especially for the forests and wetlands. Wetlands provide multiple ecological services (e.g., a food source, climate regulation). Thus, wetland protection is part of the foundation for sustainable economic and social development for Beijing. This study summarizes the experience of well-developed cities in wetland protection and sustainable development and subsequently analyzes the current issues of Beijing’s wetlands. The results showed that a limited resource space, high human stress, and lack of scientifically based polices are the main obstacles. Therefore, we recommend the following: (1) support the utilization of rainwater and reclaimed water and optimize the coordinated utilization of water resources, (2) strengthen the ecological protection and restoration efforts to realize the ecological protection system of water–city integration, (3) build a forest water complex ecosystem in metropolises to create a livable environment with forest and water, and (4) conduct scientific and technological research on the optimal total amount of wetlands and develop wetland technologies

Ecological Approach for the Evaluation of Structure and Sustainability in the Tourism Industry

Badaling is the main tourism area in Beijing. The development of tourism has generated considerable economic benefit in this region, but the tourism industry also brought considerable environmental pressure. To obtain a targeted upgrade plan for metropolitan tourism industry, static and dynamic analysis methods were used to quantitatively estimate the structure of the tourism industry in this region. In addition, the ecological footprint and ecosystem capacity models were used to evaluate the sustainable development of tourism. The results show that: (1) The structure of tourism in Badaling is better than that of Beijing, but the growth rate of tourism earnings is slower than the average value in Beijing. Overall, the region lacks competitiveness and the tourism industry in the area is in dire need of an upgrade; (2) the total ecological footprint due to tourism in the Badaling region is 381,098.28 hm2, and the ecosystem capacity is 4509.61 hm2. It is in an obvious ecological deficit, and the development of the tourism industry is unsustainable. To relieve the pressure on the ecology in the Badaling region, we propose four policy suggestions: (1) develop disadvantaged sectors and enhance tourism industry competitiveness, (2) boost tourist transportation revenues relying on the Winter Olympic Games, (3) grow cultural and creative products and expand sales channels, and (4) strengthen inter-regional cooperation and alleviate local ecological pressure

Ecological Approach for the Evaluation of Structure and Sustainability in the Tourism Industry

Badaling is the main tourism area in Beijing. The development of tourism has generated considerable economic benefit in this region, but the tourism industry also brought considerable environmental pressure. To obtain a targeted upgrade plan for metropolitan tourism industry, static and dynamic analysis methods were used to quantitatively estimate the structure of the tourism industry in this region. In addition, the ecological footprint and ecosystem capacity models were used to evaluate the sustainable development of tourism. The results show that: (1) The structure of tourism in Badaling is better than that of Beijing, but the growth rate of tourism earnings is slower than the average value in Beijing. Overall, the region lacks competitiveness and the tourism industry in the area is in dire need of an upgrade; (2) the total ecological footprint due to tourism in the Badaling region is 381,098.28 hm2, and the ecosystem capacity is 4509.61 hm2. It is in an obvious ecological deficit, and the development of the tourism industry is unsustainable. To relieve the pressure on the ecology in the Badaling region, we propose four policy suggestions: (1) develop disadvantaged sectors and enhance tourism industry competitiveness, (2) boost tourist transportation revenues relying on the Winter Olympic Games, (3) grow cultural and creative products and expand sales channels, and (4) strengthen inter-regional cooperation and alleviate local ecological pressure